(i) Technical Field
The present invention relates to electrostatic-image developing toners, electrostatic image developers, and toner cartridges.
(ii) Related Art
Recently, electrophotographic processes have been used in a wide range of applications, from copiers to office network printers, PC printers, and on-demand printers, with the development of equipment and the expansion of communication networks in the information society. Accordingly, there is a growing need for high image quality, high speed, high reliability, small size and weight, and high energy efficiency both in monochrome and color electrophotographic processes.
A typical electrophotographic process involves forming a fixed image through multiple steps, including electrically forming an electrostatic image on a photoreceptor (image carrier) that uses a photoconductive material by various techniques, developing the electrostatic image with a developer containing a toner, transferring the toner image from the photoreceptor to a recording medium such as paper, either directly or via an intermediate transfer member, and fixing the transferred image to the recording medium.
To provide a toner having both low-temperature fixability and offset resistance, polyester resins, which are effective for achieving low-temperature fixability, are useful as binder resins. However, in a situation where an image-forming apparatus starts image formation immediately after power-on from a power-off state in a low-temperature, low-humidity environment, e.g., in winter, it is possible that the fixing member of the fixing device has yet to reach a predetermined temperature range. This may make it difficult to supply a sufficient amount of heat to fix a toner image to a recording medium. Thus, the fixing member tends to have an insufficient amount of heat to melt a toner image, and the use of a toner containing a polyester resin as a binder resin may result in cold offset.